Hydrochemical, Isotopic, and Geophysical Studies Applied to the Evaluation of Groundwater Salinization Processes in Quaternary Beach Ridges in a Semiarid Coastal Area of Northern Patagonia, Argentina

Quaternary sea level fluctuations have led to the development of beach ridges on many South Atlantic coasts. The objective of this paper was to asses from lithological, hydrochemical, isotopic, and geophysical studies the salinization processes affecting groundwater stored in Pleistocene and Holocene beach ridges of the northern Patagonian coast. A hydrogeomorphological characterization of the area was performed using digital elevation models, the interpretation of satellite images, and field studies. Vertical electrical soundings were performed on transects running perpendicular to beach ridges in order to define variations in the freshwater-saltwater interface position. The salinity, chemistry, and stable isotopes of the groundwater were analyzed. The results demonstrated that the groundwater salinization of Pleistocene ridges responds to processes associated with the geological-geomorphological evolution of the area. The cementation of these surface sediments limits rainwater infiltration, which consequently prevents the development of freshwater lenses. This suggests that saline water is the result of ancient marine ingressions. Freshwater lenses develop in Holocene beach ridges; however, slight water salinization is detectable in the most populated areas as a result of intensive exploitation. The data provided are useful for freshwater resource prospection along the arid coast of Patagonia, where beach ridge deposits abound and populations experience serious drinking water supply problems.

Presence of Arsenic in Potential Sources of Drinking Water Supply Located in a Mineralized and Mined Area of the Sierra Madre Oriental in Mexico

Mine wastes from the La Aurora mine in the state of Guanajuato were generated by the flotation process and placed in four tailing dumps on the local stream while the plant operated. Given that these wastes contain toxic elements, it is important to establish their impact on the quality of several surrounding natural sources of water that are considered potential drinking water supplies. This study identified four water source types, in which the contents of arsenic (As), mercury (Hg), and thallium (Tl) were exceeded, according to international guideline values for drinking water quality. The first type of aqueous sample corresponded to leachates produced by rainwater infiltration in tailings and water–mineral waste interactions. The second type corresponded to surface water along the Xichú and La Laja Streams, and the third and fourth types involved two groundwater well samples and spring samples, respectively. The Chiquito Stream was used as a reference area that had not been impacted by the mine wastes. The isotopic signatures associated with δ34Ssulfate and δ18Osulfate compositions from the El Ojo de Agua spring are similar to those of the Santa María River and are different from those of the mine waste leachates. This study shows evidence of the presence of As in the El Ojo de Agua spring, which results from dissolution of secondary mineral phases that were produced by alteration of the mine wastes, which then migrated along the Xichú Stream system until reaching the spring. These As-bearing fine particles are prone to dissolution when in contact with this water source. Principal component analysis revealed that the observed As, Tl, and Hg can be attributed to weathering of the mine wastes. However, the results suggest that a natural contribution of these elements could be associated with rainwater–igneous rock interactions.

Use of Multidisciplinary Approaches for Groundwater Recharge Mechanism Characterization in Basement Aquifers: Case of Sanon Experimental Catchment in Burkina Faso

In Burkina Faso, the basement aquifers represent a major asset in terms of quantity and quality, for both drinking and irrigation purposes for rural populations. They provide water resources that can guarantee the long-term needs of the populations, provided that a sustainable management policy for these resources is adopted. Yet, any groundwater resource management policy is necessarily linked to a better knowledge of aquifer recharge mechanisms, which is yet to be fully assessed in the Sahelian basement area. The objective of this study was to characterize the recharge mechanism within the experimental site of Sanon, located in the basement zone in Burkina Faso, using a coupling of hydrodynamic and chemical approaches. The hydrodynamic approach consisted of monitoring the spatial and temporal distribution of the piezometric levels of the aquifers along a north–south and east–west transect and determining soil infiltration capacity. The hydrochemical characterization of the aquifers was carried out through an analysis of groundwater samples from the concerned aquifers and daily tracing of the electrical conductivity of the aquifer water. The cross-analysis from the results of the implemented approaches shows a direct recharge mechanism through rainwater infiltration in the central valley, an indirect recharge mechanism in the lowlands, and a recharge mechanism by lateral transfers in the peripheral aquifers of the Sanon experimental catchment. The existence of a piezometric dome reveals in the central valley a zone of preferential recharge and water movement. The water of the central valley is the least mineralized with electrical conductivities below 100 µS/cm. This mineralization follows the direction of the water flow.

Pembuatan dan Edukasi Pentingnya Lubang Resapan Biopori (LRB) untuk Membantu Meningkatkan Kesadaran Mengenai Sampah Organik serta Ketersediaan Air Tanah di Dusun Tumang Sari Cepogo

Generally, Tumang Sari, Cepogo is dry land in the form of yards, fields, and plantations. Low environmental awareness in Tumang Sari regarding rainwater infiltration and organic waste management results in environmental problems such as waterlogging, garbage accumulation and health problems. Biopore Infiltration Hole (LRB) is expected to be a solution to these environmental problems. This program aims to increase public understanding of how to optimize rainwater catchment areas and overcome the problem of organic waste. The methods used are socialization and delivery of materials, training and assistance in making LRB, as well as post-activity monitoring and evaluation. The results obtained are improvement knowledge, understanding and skills of the Tumang Sari community after the socialization and assistance by the KKN-T Team. The LRB socialization and development program which was carried out in Tumang Sari received good support and response from the government and the local community. Socialization activities and the practice of making LRB is hoped can reduced the volume of puddles and the organic waste in the LRB begun to decomposed and became to be compost.

Influence of Rainwater Infiltration in Partial Anti-Seepage Bioretention on Adjacent Municipal Roads in Different Collapsible Grades Loess Sites

It is practical to carry out sponge cities to manage rain and floods in collapsible loess areas where water resources and water disasters are prominent. The infiltration laws of the partial anti-seepage bioretention in collapsible loess fields are helpful to ensure the effectiveness and safety of sponge city, which were learned from the field test and numerical model. The seepage field and displacement field of loess sites with different collapsibility grades were compared during rainwater infiltration of the bioretention with the numerical model; the suitability and optimization suggestions for foundation treatment of this structure in various sites were proposed. It is found that the infiltration characteristics can be divided into three stages, and the infiltration range of bioretention increases with increasing infiltration time under the same site type, and the higher the collapsibility level of the site is, the more significant the rise in infiltration range. The settlement of adjacent roads in class II and III collapsible fields is far greater than that in class I and is greater than the settlement standard. The facilities’ bottom part foundation can be replaced to ensure the functionality of the facilities and the safety of the surrounding roads in the actual project.

ANALISIS KEBUTUHAN U-DITCH DAN BUIS BETON SEBAGAI SARANA DRAINASE GANG

Given the conditions in the hamlet Nandan Sariharjo Ngaglik Sleman: 1) alley drainage and rainwater conservation substandard, 2) maintenance of channels drainage alley by the people who have not been up. Purpose of applying science and technology for communities in Nandan's Hamlet: 1) the smooth flow of rainwater in the lower reaches of the drainage so as not to occur puddle in an alley, 2) smoothness of rainwater infiltration in the alley by using infiltration wells. Activity Field of physical infrastructure includes. 1) installation of drainage passage, downstream in RT 02, 2) installation of alley infiltration wells for water conservation in RT 01. Methods of Implementation Activities: 1) extension: the installation and maintenance procedures drainage and infiltration wells alley, 2) mentoring: planning, implementation, and supervision of the installation of drainage and infiltration wells alley. With outputs: 1) channel u drainage ditch covered alley 30 x 40 x 120 cm of concrete K-350 along a slope of 20,4 m channel = 0,02 = 1/50, velocity = 1,52 m/s, and discharge: 0,2 m/det3, 2) well impregnating alley of concrete pipe K-300, Ø 80 cm depth of 4 m by five pieces with moderate soil permeability (loam/silt, 2,0 to 6,5 cm/hour) can absorb wide field rainfed 503 m2.